Home Itens selecionados Provedores de dados OAI Créditos Sobre Ajuda

			Busca avançada
	Provedor de dados 70 (13) 63 (11) 90 (10) 91 (9) 31 (5) 5 (5) 53 (4) 118 (3) 1 (2) 124 (2) 14 (2) 86 (2) 111 (1) 190 (1) 3 (1) 64 (1) 94 (1) Mais... Autor Reichardt,K. (5) English, Burton C. (4) Galea,Manuel (4) Mahajanashetti, S.B. (4) Roberts, Roland K. (4) Uribe-Opazo,Miguel A. (4) Ferraz,Gabriel A. e S. (3) Vieira,Sidney Rosa (3) Bacchi,O.O.S. (2) Bazzi,Claudio L. (2) Bottega,Eduardo L. (2) Carvalho,Morel de Passos e (2) Coelho, Antonio Eduardo (2) Dafonte,Jorge Dafonte (2) Dalposso,Gustavo H. (2) Dourado-Neto,D. (2) Ferraz,Patrícia F. P. (2) Gontijo,Ivoney (2) Guedes Filho,Osvaldo (2) Guedes,Luciana P. C. (2) Mais... Palavra-chave Spatial variability (73) Geostatistics (17) Precision agriculture (12) Precision farming (5) Semivariogram (5) Management zones (4) Kriging (3) Corn (2) Fuzzy logic (2) Grain yield. (2) Interpolation (2) Maximum likelihood (2) Meta-response functions (2) Neutron probe (2) Nitrogen (2) Nitrogen restriction (2) Nitrogen side-dress (2) Nutrients (2) Optimization (2) Research and Development/Tech Change/Emerging Technologies (2) Mais... Tipo do documento Info:eu-repo/semantics/article (58) Text (5) Conference Paper or Presentation (3) Journal article (3) Journal Article (2) Folhetos (1) Parte de livro (1) Mais... Ano 2020 (2) 2019 (9) 2018 (7) 2017 (2) 2016 (10) 2015 (2) 2014 (9) 2013 (3) 2012 (4) 2011 (4) 2010 (2) 2009 (3) 2007 (1) 2006 (1) 2004 (2) 2003 (1) 2002 (2) 2001 (2) 1999 (2) 1997 (2) Mais... País Brazil (59) France (5) United States (5) Chile (3) China (1) Idioma Inglês (70) Português (3)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 73 Primeira ... 1 2 3 4 ... Última Can an increase in nitrogen rate mitigate damages caused by uneven spatial distribution of maize plants at the sowing row? 1 Kolling, Daniel Fernando; Sangoi, Luís; Leolato, Lucieli Santini; Panison, Fernando; Coelho, Antonio Eduardo; Kuneski, Hugo François. An uneven distribution of maize plants at the sowing row can decrease grain yield. This work was carried out to evaluate the effect of an increasing nitrogen rate on maize agronomic performance under different variation coefficients of plant spatial distributions at the sowing row. The experiment was conducted in Lages, Santa Catarina State, South Brazil. Three variation coefficients (VC) of plant spatial distribution (0, 50, and 100%) were tested. At the 0 level, seeds were evenly distributed 17 cm from each other. In the other treatments with uneven spatial distributions, the distances between two neighbouring seeds ranged from 2 to 54 cm. Four nitrogen side-dress rates (0, 125, 250, and 375 kgN ha-1) were evaluated. The increase in VC of plant spatial... Tipo: Info:eu-repo/semantics/article Palavras-chave: Zea mays; Spatial variability; Nitrogen side-dress; Grain yield.. Ano: 2019 URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/39874 Can an increase in nitrogen rate mitigate damages caused by uneven spatial distribution of maize plants at the sowing row? 1 Kolling, Daniel Fernando; Sangoi, Luís; Leolato, Lucieli Santini; Panison, Fernando; Coelho, Antonio Eduardo; Kuneski, Hugo François. An uneven distribution of maize plants at the sowing row can decrease grain yield. This work was carried out to evaluate the effect of an increasing nitrogen rate on maize agronomic performance under different variation coefficients of plant spatial distributions at the sowing row. The experiment was conducted in Lages, Santa Catarina State, South Brazil. Three variation coefficients (VC) of plant spatial distribution (0, 50, and 100%) were tested. At the 0 level, seeds were evenly distributed 17 cm from each other. In the other treatments with uneven spatial distributions, the distances between two neighbouring seeds ranged from 2 to 54 cm. Four nitrogen side-dress rates (0, 125, 250, and 375 kgN ha-1) were evaluated. The increase in VC of plant spatial... Tipo: Info:eu-repo/semantics/article Palavras-chave: Zea mays; Spatial variability; Nitrogen side-dress; Grain yield.. Ano: 2019 URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/39874 Limnology of a lateral lagoon system connected to a Neotropical reservoir (Rosana reservoir, São Paulo/Paraná, Brazil) 3 Ferrareze, Mateus; Instituto de Biociências; Nogueira, Marcos Gomes; Instituto de Biociências; Sartori, Luciana; Instituto de Biociências. The aim of this work was to perform a comparative analysis of four lateral lagoons and of the main channel of the Rosana Reservoir (Paranapanema river), southeast Brazil. The fieldwork was conducted during dry and rainy periods of 2004 and 2005. The analyzed variables were chlorophyll a, turbidity, total phosphorus, total nitrogen, dissolved nutrients (ammonium, nitrate, nitrite, phosphate and silicate), Secchi disk transparency, suspended solids, temperature, pH, dissolved oxygen and electrical conductivity. Intense summer rainfall provided a high input of allochthonous material into the system, resulting in conspicuous changes - high turbidity and nutrient concentrations and low transparency, especially in the reservoir channel. The cluster analysis... Tipo: Info:eu-repo/semantics/article Palavras-chave: Ecologia Limnologia floodplain; Nutrients; Paranapanema river; Limnological variables; Spatial variability; Eutrophication Ecologia. Ano: 2014 URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/21491 Design and evaluation of a yield monitoring system for combinable crops 111 Kargarpour, Hoda; Razavi, Jalil; Hemmat, Abbas; Salar, Mahmood Reza. The existence of spatial variability within fields can be beneficial if inputs for arable crop are given to the field according to locally determined requirements. While yield mapping has become an important part of precision farming strategies, the goal of this paper is to plot a yield map by the application of yield monitoring components. A yield monitoring system capable of providing sufficient reliable data to plot a yield map for small grain fields in central regions of Iran was developed. The system consisted of an impact flow sensor determining the mass flow of grain, the GPS receiver determining geographical position of the machine, two shaft encoders measuring the speed of the combine, an ultrasonic sensor measuring the actual cutting width, and a... Tipo: Info:eu-repo/semantics/article Palavras-chave: Wheat; Spatial variability; Yield map; Mass flow sensor; Precision farming. Ano: 2016 URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3608 Geostatistical analysis of crop yield maps in a long term no tillage system 53 Guedes Filho,Osvaldo; Vieira,Sidney Rosa; Chiba,Marcio Koiti; Grego,Célia Regina. It is known, for a long time, that crop yields are not uniform at the field. In some places, it is possible to distinguish sites with both low and high yields even within the same area. This work aimed to evaluate the spatial and temporal variability of some crop yields and to identify potential zones for site specific management in an area under no-tillage system for 23 years. Data were analyzed from a 3.42 ha long term experimental area at the Centro Experimental Central of the Instituto Agronômico, located in Campinas, Sao Paulo State, Brazil. The crop yield data evaluated included the following crops: soybean, maize, lablab and triticale, and all of them were cultivated since 1985 and sampled at a regular grid of 302 points. Data were normalized and... Tipo: Info:eu-repo/semantics/article Palavras-chave: Spatial variability; Cross semivariogram; Management zones. Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052010000500003 Spatial soil sampling design using apparent soil electrical conductivity measurements 53 Siqueira,Glécio Machado; Dafonte,Jorge Dafonte; González,Antonio Paz; Vázquez,Eva Vidal; Armesto,Monteserrat Valcarcel; Guedes Filho,Osvaldo. ABSTRACT Soil sampling is an important stage of digital soil mapping. The objective of this study was to characterize the spatial design of soil sampling using soil apparent electrical conductivity (ECa) and its optimized spatial sampling. For the characterization, it was used the Spatial Simulated Annealing (SSA) technique, incorporated on the software SANOS 0.1, and the method of response surface sampling design on the software ESAP 2.35. The ECa was measured at 1,887 points in an area of 6 ha located in the northwestern region of Spain. The EM38-DD equipment (Geonics Limited 2005) was used at 2 depths: vertical dipole (1.5 m effective measurement depth) and horizontal dipole (0.75 m effective measurement depth). Semivariogram showed trend for ECa in... Tipo: Info:eu-repo/semantics/article Palavras-chave: Geostatistics; Semivariogram; Spatial variability; Optimization; Soil sampling. Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052016000400459 Mapping of soil micronutrients in an european atlantic agricultural landscape using ordinary kriging and indicator approach 53 Dafonte,Jorge Dafonte; Guitián,Montserrat Ulloa; Paz-Ferreiro,Jorge; Siqueira,Glécio Machado; Vázquez,Eva Vidal. Nutrient maps based on intensive soil sampling are useful to develop site-specific management practices. Geostatistical methods have been widely used to determine the spatial correlation and the range of spatial dependence at different sampling scales. If spatial dependence is detected, the modelled semivariograms can then be used to map the interested variable by kriging, an interpolation method that produces unbiased estimates with minimal estimation variance. The objectives of this paper were to examine and to map the spatial distribution of the micronutrients Cu, Zn, Fe and Mn on an agricultural area in Galicia, Spain, under European Atlantic climatic conditions. The ordinary kriging was first used to determine the values for the non-sampled locations,... Tipo: Info:eu-repo/semantics/article Palavras-chave: Soil management; Geostatistics; Spatial variability; Soil chemistry. Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052010000500018 Analysis of the spatial variability of crop yield and soil properties in small agricultural plots 53 Vieira,Sidney Rosa; Paz Gonzalez,Antonio. The objective of this study was to assess spatial variability of soil properties and crop yield under no tillage as a function of time, in two soil/climate conditions in São Paulo State, Brazil. The two sites measured approximately one hectare each and were cultivated with crop sequences which included corn, soybean, cotton, oats, black oats, wheat, rye, rice and green manure. Soil fertility, soil physical properties and crop yield were measured in a 10-m grid. The soils were a Dusky Red Latossol (Oxisol) and a Red Yellow Latossol (Ultisol). Soil sampling was performed in each field every two years after harvesting of the summer crop. Crop yield was measured at the end of each crop cycle, in 2 x 2.5 m sub plots. Data were analysed using semivariogram... Tipo: Info:eu-repo/semantics/article Palavras-chave: Spatial variability; Kriging; Yield map; Semivariogram. Ano: 2003 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052003000100016 Spatial dependence and experimental precision in snap bean ( Phaseolus vulgaris L.) trials related to the number of plants and harvests 64 Lúcio,Alessandro Dal'Col; Benz,Vilson; Storck,Lindolfo; Cargnelutti Filho,Alberto. ABSTRACT The productive variability in horticultural crops affects the planning and quality of the experiments, leading to wrong conclusions. The objectives of this study were to verify the spatial dependence of the fresh biomass of snap beans and to dimension the number of plants and harvests that are necessary to improve experimental accuracy in trials. The data of the fresh biomass of snap beans from uniformity trials carried out in a greenhouse and in the field with semivariograms were created with data transformed into indicators. Thus, they were combined on scenarios of plot size and harvest grouping, and they were adjusted to the spherical, exponential and Gaussian models. A response surface was also applied, with the variation coefficient as a... Tipo: Info:eu-repo/semantics/article Palavras-chave: Geostatistic; Spatial variability; Multiple regression models; Experiment planning; Variation coefficient. Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542016000200184 Local influence when fitting Gaussian spatial linear models: an agriculture application 118 Grzegozewski,Denise M; Uribe-Opaz,Miguel A; De Bastiani,Fernanda; Galea,Manuel. D.M. Grzegozewski, M.A. Uribe-Opazo, F. De Bastiani, and M. Galea. 2013. Local influence when fitting Gaussian spatial linear models: an agriculture application. Cien. Inv. Agr. 40(3): 523-535. Outliers can adversely affect how data fit into a model. Obviously, an analysis of dependent data is different from that of independent data. In the latter, i.e., in cases involving spatial data, local outliers can differ from the data in the neighborhood. In this article, we used the local influence technique to identify influential points in the response variables using two different schemes of perturbations. We applied this technique to soil chemical properties and soybean yield. We evaluated the effects of the influential points on the spatial model selection,... Tipo: Journal article Palavras-chave: Geostatistical; Influence diagnostics; Maximum likelihood; Outliers; Spatial variability. Ano: 2013 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202013000300006 Spatial variability of soil chemical attributes and productivity and the chemical and physical properties of oranges 118 Nicolau,Rafaela F; Mercante,Erivelto; Maggi,Marcio F; de Souza,Eduardo G; Gasparin,Eloi. The purpose of this study was to analyze the spatial variability of soil properties and productivity and the chemical and physical properties of oranges (Monte Parnaso variety) in their geographical quadrants. This experiment was conducted in a commercial orange orchard in the municipality of Nova Laranjeiras in the State of Paraná, Brazil. A GPS receiver and a total station were used to measure the spatial location of the fruit and to determine which quadrant they were located in. In this experiment, 13 trees were studied. Twelve fruits were evaluated in each geographical quadrant, and 156 fruits were considered. After harvest, the productivity was expressed as kg per quadrant (kg quadrant-1). Next, physical tests (equatorial diameter (EqD), total fruit... Tipo: Journal article Palavras-chave: Citriculture; Geostatistics; Spatial variability. Ano: 2014 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202014000300006 Optimization of sample design sizes and shapes for regionalized variables using simulated annealing 118 Guedes,Luciana P.C; Uribe-Opazo,Miguel A; Ribeiro Junior,Paulo J. The spatial variability of structures in regionalized variables are defined with the aid of geostatistical techniques, which facilitate the estimation of values for these variables in unsampled localizations and generate thematic maps to be used in decision making for localized treatments in the area under study. The quality of these maps depends on the trustworthiness of these estimates that can be modified with the choice for the sample design. The objective of this work was to establish an optimal size and shape of the sample designs in order to enhance the efficiency of sampling plans for the prediction of space dependent variables. These designs were obtained with the use of a stochastic search method called Simulated Annealing. This method is based... Tipo: Journal article Palavras-chave: Geostatistics; Interpolation; Precision agriculture; Spatial variability. Ano: 2014 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202014000100004 SOIL ATTRIBUTES AND WHEAT PERFORMANCE IN A GEOREFERENCED SEED PRODUCTION FIELD 70 Gadotti,Gizele I.; Corrêa,Marciabela F.; Navroski,Renan; Nadal,Ariele P.; Schuch,Luis O. B.. ABSTRACT The aim of this research was to study the linear correlations and spatial distribution between soil attributes and productivity and physiological quality of wheat seeds. Soil samples were collected at georeferenced points in an area of 41 ha with a rectangular grid of 100 × 100 m to determine soil fertility. Grain productivity, number of ears m-2, protein content, and physiological seed quality were assessed. The results were submitted to Pearson's correlation analysis, descriptive statistics, and geostatistics. Phosphorus content presented a high spatial variability, with a coefficient of variation of 97.79%. Protein content, number of ears, and SMP index presented low values of coefficient of variation, indicating their low spatial variability.... Tipo: Info:eu-repo/semantics/article Palavras-chave: Precision agriculture; Fertility; Seed quality; Triticum aestivum L.; Spatial variability. Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000400624 Technical evaluation of artificial ligthing systems for broiler houses 70 Pereira,Priscilla A.; Yanagi Junior,Tadayuki; Silva,Joaquim P. da; Lima,Renato R. de; Campos,Alessandro T.; Abreu,Lucas H. P. The spatial distribution of illuminance and the electric consumption of artificial lighting system is one of the main problems related to broiler production. Therefore, the aim of this study was to evaluate the spatial distribution of luminance level and energy efficiency of different lighting systems for broiler houses. Six types of lamps were tested in two different configurations to find the minimum illuminance of 20 and 5 lux. The tested lamps were incandescent (IL) 100 W, compact fluorescent (CFL) 34 W, mixed (ML) 160 W, sodium vapor (SVL) 70 W, T8 fluorescent tube (T8 FTL) 40 W and T5 fluorescent tube (T5 FTL) 28 W. The first four were evaluated with and without reflective light fixture and the latter two without light fixture. It was observed that... Tipo: Info:eu-repo/semantics/article Palavras-chave: Artificial lighting; Spatial variability; Energy efficiency; Aviculture. Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000600002 SENSOR SYSTEMS FOR MAPPING SOIL FERTILITY ATTRIBUTES: CHALLENGES, ADVANCES, AND PERSPECTIVES IN BRAZILIAN TROPICAL SOILS 70 Molin,José Paulo; Tavares,Tiago Rodrigues. ABSTRACT Soil fertility attributes have different scales and forms of spatial and temporal variations in agricultural fields. Adequate spatiotemporal characterization of these attributes is fundamental to the successful development of strategies for variable rate application of fertilizers, enabling the classic benefits of precision agriculture (PA). Studies on Brazilian soil have shown that at least 1 sample ha-1 is required for the reliable mapping of key fertility attributes. However, this sampling density is difficult owing to the operational challenges of sample collection and the cost of laboratory analyses. Given this limitation, soil sensors have emerged as a practical and complementary technique for obtaining information on soil attributes, at... Tipo: Info:eu-repo/semantics/article Palavras-chave: Spatial variability; Spectroscopy; On-the-go sensing; Hybrid laboratory. Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000800126 Soybean yield maps using regular and optimized sample with different configurations by simulated annealing 70 Guedes,Luciana P. C.; Ribeiro Junior,Paulo J.; Uribe-opazo,Miguel A.; Bastiani,Fernanda de. ABSTRACT This study aimed to compare thematic maps of soybean yield for different sampling grids, using geostatistical methods (semivariance function and kriging). The analysis was performed with soybean yield data in t ha-1 in a commercial area with regular grids with distances between points of 25x25 m, 50x50 m, 75x75 m, 100x100 m, with 549, 188, 66 and 44 sampling points respectively; and data obtained by yield monitors. Optimized sampling schemes were also generated with the algorithm called Simulated Annealing, using maximization of the overall accuracy measure as a criterion for optimization. The results showed that sample size and sample density influenced the description of the spatial distribution of soybean yield. When the sample size was... Tipo: Info:eu-repo/semantics/article Palavras-chave: Accuracy indices; Optimization; Sampling grids; Spatial variability. Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000100114 BED TEMPERATURE IN COMPOST BARNS TURNED WITH ROTARY HOE AND OFFSET DISC HARROW 70 Mota,Vania C.; Andrade,Ednilton T. de; Leite,Daniel F.. ABSTRACT The success of confinement for dairy cattle in the compost barn model depends mainly on the management of the bed and consists of its turning. This paper characterises the spatial variability of the bed temperature in the compost barn confinement model, as well as verifying whether there was an effect on efficiency from turning the bed with different agricultural implements. The experiment was conducted during the summer and winter of 2016, with 8 days of collection in each period. Data were analysed with descriptive statistics methods and geostatistical modelling with semivariograms and kriging maps. The results of the t-test at a5% significance level indicated that, after turning the bed with the plough or rotary hoe, the temperature values were... Tipo: Info:eu-repo/semantics/article Palavras-chave: Aeration/oxygenation of the bed; Dairy cattle; Confinement; Agricultural implements; Spatial variability. Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000300280 Management zones definition using soil chemical and physical attributes in a soybean area 70 Bazzi,Claudio L.; Souza,Eduardo G.; Uribe-Opazo,Miguel A.; Nóbrega,Lúcia H. P.; Rocha,Davi M.. Several equipments and methodologies have been developed to make available precision agriculture, especially considering the high cost of its implantation and sampling. An interesting possibility is to define management zones aim at dividing producing areas in smaller management zones that could be treated differently, serving as a source of recommendation and analysis. Thus, this trial used physical and chemical properties of soil and yield aiming at the generation of management zones in order to identify whether they can be used as recommendation and analysis. Management zones were generated by the Fuzzy C-Means algorithm and their evaluation was performed by calculating the reduction of variance and performing means tests. The division of the area into... Tipo: Info:eu-repo/semantics/article Palavras-chave: Precision agriculture; Spatial variability; Fuzzy clustering; Management zones; Autocorrelation; Cross-correlation. Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000500007 Management zones in agriculture acording to the soil and landscape variables 70 Delalibera,Hevandro C.; Weirich Neto,Pedro H.; Nagata,Noemi. The study of spatial variability of soil and plants attributes, or precision agriculture, a technique that aims the rational use of natural resources, is expanding commercially in Brazil. Nevertheless, there is a lack of mathematical analysis that supports the correlation of these independent variables and their interactions with the productivity, identifying scientific standards technologically applicable. The aim of this study was to identify patterns of soil variability according to the eleven physical and seven chemical indicators in an agricultural area. It was used two multivariate techniques: the hierarchical cluster analysis (HCA) and the principal component analysis (PCA). According to the HCA, the area was divided into five management zones: zone... Tipo: Info:eu-repo/semantics/article Palavras-chave: Multivariate analysis; Precision agriculture; Spatial variability. Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000600021 MODELING OF PHOSPHORUS LOSSES BY WATER EROSION 70 Farias,Vera L. da S.; Martins Filho,Marcílio V.; Paula,Daniela T. de; Siqueira,Diego S.. ABSTRACT Phosphorus losses in runoff water and eroded sediment may increase the risk of eutrophication. Erosion prediction models can be used to assess and quantify nutrient losses and transport in different soil management scenarios. This study aimed to assess the performance of models to estimate the losses of available phosphorus in eroded sediments and assess their spatial variability pattern. The experiment was installed on a eutrophic Red Ultisol located in Tabapuã, northwestern São Paulo State, São Domingos Stream Watershed. Aiming at estimating and validating the models, measurements were made from 2007 to 2015 at 17 observation points (slopes), determining soil phosphorus content (Psoil), eroded sediments (Psed), and enrichment rate (ERsed). The... Tipo: Info:eu-repo/semantics/article Palavras-chave: WEPP model; Enrichment rate; Spatial variability. Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000100149 Registros recuperados: 73 Primeira ... 1 2 3 4 ... Última

Empresa Brasileira de Pesquisa Agropecuária - Embrapa Todos os direitos reservados, conforme Lei n° 9.610 Política de Privacidade Área restrita		Embrapa Parque Estação Biológica - PqEB s/n° Brasília, DF - Brasil - CEP 70770-901 Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco